Turbine rotor



May 25. 1943. A. w. CARLSON TURE INE ROTOR Filed Feb. 1, 1941 2 Sheets-Sheet 1 y 1943- A. w. CARLSON 2,319,846

TURBINE ROTOR Fiied Feb. 1, 1941 2 Sheets-Sheet 2 Patented May 25, 1943 TURBINE ROTOR Axel Carlson, Worcester, Mass, assignor to Carling Turbine Blower 00., Worcester, Mass, a corporation of Massachusetts Application February 1, 1941, Serial No. 377,039

3 Claims.

This invention relates to rotors for steam or air turbines or other similar machines. The blades or vanes in such rotors are worn away rapidly by the high velocity of the steam or air blast and must be frequently replaced.

It is the general object of my invention to provide an improved construction by which separately formed turbine blades may be conveniently and securely mounted on the periphery of a turbine rotor and may be easily removed and replaced when worn or broken.

A further object is to provide a construction in which a complete set of blades may be assembled for insertion as a unit in said rotor, and in which all of said blades may be secured in place by a single clamping device.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

Preferred forms of the invention are shown in the drawings, in which Fig. 1 is a partial side elevation of a singlestage rotor, partly in section;

Fig. 2 is a partial side elevation of the rotor, partly in section and looking in the direction of the arrow 2 in Fig. 1;

Fig. 3 is a partial exploded sectional view of the several parts of my improved rotor;

Fig. 4 is a partial side elevation of a rotor frame member;

Fig. 5 is a partial side elevation of a clamping ring;

Fig. 6 is a partial plan view of a shroud ring;

Fig. 7 is a detail sectional view, taken along the line 1-1 in Fig. 6;

Fig. 8 is a front elevation of a rotor blade;

Fig. 9 is a side elevation thereof;

Fig. 10 is a plan view thereof;

Fig. 11 is a bottom view thereof;

Fig. 12 is a partial sectional elevation of a two-stage rotor;

Fig. 13 is a side elevation, partly broken away and looking in the direction of the arrow I3 in Fig. 12; and

Fig. 14 is a partial side elevation of a center separator ring, looking in the direction of the arrow M in Fig. 12.

Referring to Figs. 1 to 11, I will first describe a single-stage rotor embodying my improvements. This rotor comprises a rotor frame member 20, preferably formed as a casting or forging and having a hub portion 2| and a rim portion 22. The portion 22 is accurately machined to the section shown in Fig. 3 and is also trans,

versely slotted as indicated at 24 in Fig. 4 to provide a series of spacing projections 25.

The rotor blades or vanes are preferably formed of bar stock drawn to the section shown in Fig. 10 and thereafter machined to provide a short projection 3| at the upper end of each blade and a T-shaped projection 32 at the lower end of each blade. The upper projections 3| are adapted to be received in openings 36 (Fig. 6) in a shroud ring 31.

After being thus inserted, the outer ends of the projections 3| are headed over or riveted as indicated at 38 in Fig. 1, so that a complete set of blades is permanently assembled with each shroud ring. Clamping rings 40 and 4| are also provided, which rings may be identical in construction.

In assembling my improved rotor, a set of blades 30 is first assembled in a shroud ring 31 and are securely riveted therein. The entire set of blades is then inserted in the peripheral slots 24 of a rotor frame member 20, after which clamping rings 40 and 4| are assembled at the sides of the rotor and blades, and are firmly secured together by rivets 44 (Fig. 2) or in any other convenient manner.

If it is thereafter necessary to replace broken or worn blades, the rivets or fastening devices 44 are removed and one of the clamping rings, as 4!, is taken off, after which the entire set of blades may be removed as a unit and a new set may be quickly and easily inserted. During this operation, the second clamping ring, as 40, may be left in position. This ring may be permanently secured in place by additional screws, as 45 (Fig. 1), if so desired.

With the parts assembled as shown in Fig. 2, it will be evident that the blades 30 are accurately spaced and aligned and that they are very securely held from displacement by the clamping rings 40 and 4 I, which engage the T-shaped projections 32 at the lower ends of the blades 30 and securely hold the blades from either outward or lateral displacement.

In Figs. 12, 13 and 14 I have shown my invention as applied to a two-stage rotor comprising two rotor frame members and 5|, two sets of blades 52 and 53, two shroud rings 54 and 55, a center separator and. clamping ring 65, and clamping rings 62 and 63.

The rotor frame member 59 is provided with peripheral slots 65 to receive the lower ends of the blades 52 and is also provided with spaced holes 66 for clamping screws 61, the inner ends of which are threaded into the center separator ring 60.

The rotor frame member 5! is similarly machined to receive the lower ends of the blades 53 and is similarly provided with openings to receive clamping screws 68 extending through the clamping ring 63 and threaded into the center separator and clamping ring 60, all as previously described.

The parts mounted on the two rotor frame members 50 and 5| are identical in construction, except for differences in size and diameters. The blades 52 are shorter than the blades 53 and have their inner ends at a slightly greater distance from the axis of the rotor.

The usual fixed blades are mounted in the casing H of the turbine and are positioned between the two series of movable blades, as shown in Fig. 12 and in accordance with the usual 7 practice.

It will e evident that either series of blades 52 or 53 may be removed and replaced by removing the corresponding clamping ring 62 or 63.

' of rotor frame members each having a rim portion with spaced peripheral slots therein, a center separator ring positioned between the rim portions of said rotor frame members, a plurality of blades mounted in said slots in said frame members, a recessed clamping ring secured to the outside of each frame member and engaging the blades in said member and holding each blade from radial or transverse displacement therein, and means to detachably secure said clamping rings, said frame members and said center separator ring together.

2. A two-stage turbine rotor comprising a pair of rotor frame members each having a rim portion with spaced peripheral slots therein, a center recessed separator ring positioned between the rim portions of said rotor frame members, a, plurality of blades mounted in said slots in said frame members and having enlarged inner end portions engaged by said separator ring, a clamping rin secured to the outside of each frame member and engaging the blades in said member and holding each blade from radial or transverse displacement therein, and means to detachably secure said clamping rings, said frame members and said center separator ring together.

3. A turbine rotor comprising a rotor frame member having a rim portion with spaced transverse slots therein, a plurality of blades for said rotor having laterally enlarged T-shaped inner end projections mounted in said slots, clamping rings recessed to receive end portions of said T-shaped projections, and means to secure said rings at the sides of said frame member, the outer circumferential portions of said rings extending axially inward over the ends of said T-shaped projections and said rings holding each separate blade from either radial or transverse displacement in said frame member, and the spaced slots in said frame member holding each separate blade from circumferential displacement in said member.

AXEL W. CARLSON. 

